The Hoops will take another step towards clinching the Scottish Premiership title with a win against St Mirren at home on Saturday, but the Parkhead manager is already pressing ahead with plans for next season.
The Northern Irishman expects to lose some players at the end of the current campaign, with forward Georgios Samaras out of contract at the end of the season and speculation surrounding the future of Dutch defender Virgil van Dijk and keeper Fraser Forster, both of whom have been in fine form this season.
To that end, Lennon has lined up "more than several" replacements.
"We have an extensive list of players that we are looking at with a view to bringing here in the summer," he said. "We are certainly looking at four or five positions.
"I am pretty sure that players will be leaving in the summer. I have no indication of how many but players will be leaving, I would imagine.
"Striker is always a priority position but at the minute we have very good players in that position.
"Leigh (Griffiths) is just in the door and he is really settling in well and we are very pleased with the contribution he is making. But if there is a quality striker out there that we can afford, and we feel can make us better, we will pursue it."
Lennon, however, described reports linking him to Manchester United forward Federico Macheda as "wild speculation".
Giovanni Bia, the agent of the 22-year-old who is currently on loan at Birmingham, was quoted as saying that both Celtic and Rangers are interested in the player.
However, the former Celtic skipper said: "There is nothing in that story at all. We have been aware of his availability over previous transfer windows but have not pursued that.
"You never say never but it is just wild speculation at the minute."
Lennon, admits he is concerned by the fitness issues which continue to surround wide-man Derek Boerrigter, who will miss the visit of the Buddies with an abdominal problem.
The 27-year-old Dutchman, who signed from Ajax last summer, has not had a run of games this season after being taken off injured in his debut against Ross County at Parkhead in August.
His frustrations appeared to boil over in a recent interview when he was quoted as saying: "It is my intention to get into the starting line-up in the foreseeable future. If that doesn't happen I will have to go and knock on the manager's door and we will need to talk. I have not come over here to sit on the bench."
However, Lennon said: "I saw the interview and I am quite comfortable with everything he said. It wasn't a pop at me at all.
"He has found it frustrating because of injuries but we have played him in some big games this season.
"He is pretty happy here, he is just frustrated that the injuries have taken its toll on his flow of games.
"It is a worry. He has had a scan this week on an abdominal problem but that has come through okay.
"It has been very stop-start for him. I wouldn't say it is a major worry but it is concerning."